Chair back



A portion of the disclosure of this patent document contains material for which a claim for copyright is made. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the US Patent and Trademark Office patent file or records, but reserves all other copyrights whatsoever.

FIG. 1 is an upper perspective view of an ornamental design for a chair back;

FIG. 2 is a right elevation view thereof;

FIG. 3 is a left elevation view thereof;

FIG. 4 is a front view thereof;

FIG. 5 is a rear view thereof;

FIG. 6 is a top view thereof; and,

FIG. 7 is a bottom view thereof.

In the drawings, all styles of broken lines depict portions of the chair back that form no part of the claimed design. 

CLAIM The ornamental design for a chair back, substantially as shown and described. 